Consumers are becoming more concerned with the quality of their drinking water. When RO is used in a residential setting, water is pulled from the water line. This water is run through a sediment filter and then a carbon prefilter. The water then runs through a reverse osmosis membrane element. The concentrate stream from the membrane element flows to the drain, while the permeate water runs into a storage tank—usually with 1-2 gallon storage capacity. From the storage tank the permeate water runs through a second carbon filter (a polishing filter), then to a separate faucet usually mounted on the kitchen sink. In low pressure feed water situations, a pump is needed to increase the driving pressure across the membrane, increasing the complexity and cost of the system.